One-pot Co-precipitation Research Articles

In Situ Coupling of Carbon Dots with Co-ZIF Nanoarrays Enabling Highly Efficient Oxygen Evolution Electrocatalysis.

Metal-organic frameworks (MOFs) are regarded as one promising class of precatalysts for electrocatalytic oxygen evolution reaction (OER), yet most of them suffer from poor conductivity and lack of coordinatively unsaturated metal sites, which hinders the fast electrochemical reconstruction and thus a poor OER activity. To address this issue, a unique heterocomposite has been constructed by in situ inserting carbon dots (CDs) into cobalt-based zeolitic imidazolate framework (Co-ZIF) nanosheet arrays (Co-ZIF/CDs/CC) in the presence of carbon cloth (CC) via one-pot coprecipitation for alkaline OER. Benefiting from the synergism between CDs and Co-ZIF subunits such as superior conductivity, strong charge interaction as well as abundant metal sites exposure, the Co-ZIF/CDs/CC exhibits an enhanced promotion effect for OER and contributes to the deep phase transformation from CDs-coupled Co-ZIF to CDs-coupled active CoOOH. As expected, the achieved Co-ZIF/CDs/CC only requires an overpotential of 226mV to deliver 10mA cm-2 in 1.0M KOH, which is lower than that of Co-ZIF/CC and superior to most previously reported CC-supported MOF precatalysts. Moreover, it can also maintain a large current density of 100mA cm-2 for 24h with negligible activity decay.

Development of high-performance bi-functional novel CdSnS2 atom clusters for adsorption of rose Bengal and AOP-assisted degradation of methylene blue

The fabrication of glycerol-mediated novel CdSnS2 atom clusters by one-pot co-precipitation was conducted to address rising concerns about environmental harm from hazardous organic compounds.

NiCo2O4 nano-needles as an efficient electro-catalyst for simultaneous water splitting and dye degradation.

Developing an efficient and non-precious bifunctional catalyst capable of performing water splitting and organic effluent degradation in wastewater is a great challenge. This article reports an efficient bifunctional nanocatalyst based on NiCo2O4, synthesized using a simple one-pot co-precipitation method. We optimized the synthesis conditions by varying the synthesis pH and sodium dodecyl sulfate (SDS) concentrations. The prepared catalyst exhibited excellent catalytic activity for the electrochemical oxygen evolution reaction (OER) and simultaneous methylene blue (MB) dye degradation. Among the catalysts, the catalyst synthesized using 1 g SDS as a surfactant at 100 °C provided the highest current density (658 mA cm-2), lower onset potential (1.34 V vs. RHE), lower overpotential (170 mV @ 10 mA cm-2), and smallest Tafel slope (90 mV dec-1) value. Furthermore, the OH˙ radicals produced during the OER electrochemically degraded the MB to 90% within 2 hours. The stability test conducted at 20 mA cm-2 showed almost negligible loss of the electrochemical response for OER, with 99% retention of the original response. These results strongly suggest that this catalyst is a promising candidate for addressing the challenges of wastewater treatment and energy generation.

Dye encapsulation and one-pot synthesis of microporous-mesoporous zeolitic imidazolate frameworks for CO2 sorption and adenosine triphosphate biosensing.

One-pot co-precipitation of target molecules e.g. organic dyes and the synthesis of a crystal containing microporous-mesoporous regimes of zeolitic imidazolate frameworks-8 (ZIF-8) are reported. The synthesis method can be used for cationic (rhodamine B (RhB), methylene blue (MB)), and anionic (methyl blue (MeB)) dyes. The crystal growth of the ZIF-8 crystals takes place via an intermediate phase of zinc hydroxyl nitrate (Zn5(OH)8(NO3)2) nanosheets that enabled the adsorption of the target molecules i.e., RhB, MB, and MeB into their layers. The dye molecules play a role during crystal formation. The successful encapsulation of the dye molecules was proved via diffuse reflectance spectroscopy (DRS) and electrochemical measurements e.g., cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The materials were investigated for carbon dioxide (CO2) adsorption and adenosine triphosphate (ATP) biosensing. ZIF-8, RhB@ZIF-8, MB@ZIF-8, and MeB@ZIF-8 offered CO2 adsorption capacities of 0.80, 0.84, 0.85, and 0.53 mmol g-1, respectively. The encapsulated cationic molecules improved the adsorption performance compared to anionic molecules inside the crystal. The materials were also tested as a fluorescent probe for ATP biosensing. The simple synthesis procedure offered new materials with tunable surface properties and the potential for multi-functional applications.

Fe3O4-Filled Cellulose Paper for Triboelectric Nanogenerator Application

Cellulose-based materials have recently drawn much interest due to their sustainability, biodegradability, biocompatibility, and low cost. In this present work, cellulose fiber paper (CFP) was fabricated from sugarcane leaves and used as a friction material for a triboelectric nanogenerator (TENG). Fe3O4 was incorporated to CFP triboelectric material to increase the dielectric constant of CFP for boosting power generation of TENG. The Fe3O4 filled CFP was synthesized using a facile one-pot co-precipitation technique. The effect of Fe3O4 content in CFP on dielectric property and TENG performance was investigated and optimized. The CFP filled with Fe3O4 nanoparticles exhibited the improved dielectric constant and possessed a superior TENG performance than pristine CF. The highest power density of 1.9 W/m2 was achieved, which was able to charge commercial capacitors serving as a power source for small electronic devices.

Influence of capping agents on fraction of Fe atoms occupying octahedral site and magnetic property of magnetite (Fe3O4) nanoparticles by one-pot co-precipitation method

Magnetite (Fe3O4) nanoparticles were synthesized by one-pot coprecipitation method using five different capping agents: Sodium citrate, Poly vinyl pyrrolidone (PVP), Chitosan, Cetyltrimethylammonium bromide (CTAB) and Citric acid. The influence of the various capping agents on the size, oxidation and fraction of Fe atoms occupying Octahedral against Tetrahedral sites in relation to the saturation magnetization (Ms) of the magnetite nanoparticles were studied. X-ray Absorption Fine Structure (XAFS) spectroscopy, X-ray Absorption Near Edge Structure (XANES), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier-Transform Infra-Red (FTIR) spectroscopy, Zeta potential, and Vibrating Sample Magnetometery (VSM) are used to study the various effects. The results reveal that the capping agents affect the size, oxidation and ratio of Fe atoms occupying octahedral vs tetrahedral site. The graph of Ms against size, oxidation and fraction of Fe atoms are plotted. Statistical analysis shows that Ms of the magnetite nanoparticles is highly dependent on the fraction of Fe atoms and the Size of the nanoparticles. The results reveal the Ms increases with size of the nanoparticles but decreases with the fraction of Fe atoms occupying octahedral vs tetrahedral site. However, there is no direct correlation between oxidation of Fe and Ms.

Promotional mechanism of activity of CeEuMnOx ternary oxide for low temperature SCR of NOx

Due to strong synergistic effect of the elements, a series of XEuMnOx ternary oxides (X = Ce, Ni, Co, Sb, Sn, Mo) were synthesized by one-pot co-precipitation method, and composite components were identified and optimized to maintain high activity and superior SO2 and H2O endurance in selective catalytic reduction of NOx with NH3 (NH3-SCR). NOx conversion of CeEuMnOx ternary oxide catalysts attains more than 90% at 100–250 °C, and finally achieves 74% under existence of 50 × 10−6 SO2 and 10 vol% H2O at 230 °C. The facile electron transfer through redox cycle of Mn3+ + Ce4+ ↔ Mn4+ + Ce3+ and enhanced oxygen mobility can promote formation of more Mn species in high oxidation state and chemisorbed oxygen, accelerating oxidation of NO and the adsorbed NO2 formed can facilitate “fast SCR” reaction to improve low-temperature activity. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study reveals that addition of Ce to EuMnOx catalyst boosts adsorption of NH3 and NOx species. NH3 species are activated as crucial intermediate (NH2) to promote NH3-SCR reaction. This research provides a novel material for practical deNOx application of stationary source combustion flue gas in the future.

Facile synthesis of NiO-SnO2 nanocomposite for enhanced photocatalytic degradation of bismarck brown

• The n-n type NiO-SnO 2 nanocomposite was fabricated using malic acid following a simple one-pot co-precipitation method. • Bismarck brown dye was photodegraded with an efficiency of 98 % in 70 mins under irradiation of sunlight. • The degradation showed pseudo-first-order kinetics with a rate constant of 4.5 × 10 -2 min −1 . • The photodegradation obeyed the Langmuir-Hinshelwood isotherm model. • The fabricated nanocomposite showed reusability up to 8 times. The n-n type NiO-SnO 2 nanocomposite was fabricated using malic acid following a simple one-pot co-precipitation method. The fabricated NiO-SnO 2 nanocomposite was employed as a photocatalyst to degrade bismarck brown dye under direct sunlight. TEM, SAED, XRD, XPS, EDX, FTIR, and UV spectra have been recorded to characterize the synthesized NiO-SnO 2 nanostructures. TEM studies found that the average particle size was 11 nm, and the SAED confirmed the polycrystalline nature of the synthesized nanocomposite. It was found that 98 % of 20 mg/L bismarck brown dye was degraded by 20 mg/L of photocatalyst within 70 min irradiation of sunlight at an optimum pH of 11. Further studies showed that the degradation followed pseudo-first-order kinetics with a rate constant of 4.5 × 10 -2 min −1 and obeyed the Langmuir-Hinshelwood isotherm model. The fabricated NiO-SnO 2 nanocomposite was reusable up to 8 times; hence, it proved to be an efficient catalyst for the photodegradation of bismarck brown dye.

Facile fabrication of 3D spherical Ag2WO4 doped BiOI/BiOCl double S-scheme heterojunction photocatalyst with efficient activity for mercury removal

The novel ternary Ag2WO4/BiOI/BiOCl microspherical photocatalysts were successfully fabricated by a facile one-pot coprecipitation method to accelerate the separation performance of photogenerated electron-hole (e–-h+) pairs of BiOCl and BiOI materials. The as-prepared materials were characterized by multiple methods, and the effects of various parameters such as Ag2WO4 content, fluorescent light irradiation, pH value and inorganic anions on photocatalytic removal of Hg0 were studied in detailed. The characterization results showed that the three-dimensional (3D) microspherical BiOI/BiOCl composite provided a suitable carrier for Ag2WO4, and Ag2WO4 material was evenly dispersed on the Ag2WO4/BiOI/BiOCl surface. The ternary composite possessed a larger surface area than Ag2WO4 and BiOI/BiOCl with the addition of Ag2WO4. Meanwhile, the separation efficiency of e–-h+ pairs in Ag2WO4/BiOI/BiOCl composite was greatly enhanced. The experimental results showed that Ag2WO4 content, fluorescent light irradiation, CO32− and SO2 all exhibited remarkable influences in the photocatalytic process. The Hg0 removal efficiency of Ag2WO4/BiOI/BiOCl photocatalyst was still up to 94 % after four cycles, indicating a superior stability of photocatalyst. Superoxide radical (•O2–) and hole (h+) were proved to be the main reaction substances for Hg0 removal. In view of the characterization analysis, free radicals capture test results and Density functional theory (DFT) calculation, the charge transfer route of Ag2WO4/BiOI/BiOCl composite and its mechanism for gaseous Hg0 removal were proposed with a double S-scheme mode.

Iron oxide@chlorophyll clustered nanoparticles eliminate bladder cancer by photodynamic immunotherapy-initiated ferroptosis and immunostimulation

The escape of bladder cancer from immunosurveillance causes monotherapy to exhibit poor efficacy; therefore, designing a multifunctional nanoparticle that boosts programmed cell death and immunoactivation has potential as a treatment strategy. Herein, we developed a facile one-pot coprecipitation reaction to fabricate cluster-structured nanoparticles (CNPs) assembled from Fe3O4 and iron chlorophyll (Chl/Fe) photosensitizers. This nanoassembled CNP, as a multifunctional theranostic agent, could perform red-NIR fluorescence and change the redox balance by the photoinduction of reactive oxygen species (ROS) and attenuate iron-mediated lipid peroxidation by the induction of a Fenton-like reaction. The intravesical instillation of Fe3O4@Chl/Fe CNPs modified with 4-carboxyphenylboronic acid (CPBA) may target the BC wall through glycoproteins in the BC cavity, allowing local killing of cancer cells by photodynamic therapy (PDT)-induced singlet oxygen and causing chemodynamic therapy (CDT)-mediated ferroptosis. An interesting possibility is reprogramming of the tumor microenvironment from immunosuppressive to immunostimulatory after PDT-CDT treatment, which was demonstrated by the reduction of PD-L1 (lower “off” signal to the effector immune cells), IDO-1, TGF-β, and M2-like macrophages and the induction of CD8+ T cells on BC sections. Moreover, the intravesical instillation of Fe3O4@Chl/Fe CNPs may enhance the large-area distribution on the BC wall, improving antitumor efficacy and increasing survival rates from 0 to 91.7%. Our theranostic CNPs not only demonstrated combined PDT-CDT-induced cytotoxicity, ROS production, and ferroptosis to facilitate treatment efficacy but also opened up new horizons for eliminating the immunosuppressive effect by simultaneous PDT-CDT.

One-Pot Synthesis of HRP&SA/ZIF-8 Nanocomposite and Its Application in the Detection of Insecticidal Crystalline Protein Cry1Ab.

This study reported the functionality integration of zeolitic imidazolate framework-8 (ZIF-8) with horseradish peroxidase (HRP) and streptavidin (SA) for the synthesis of a HRP&SA/ZIF-8 nanocomposite through one-pot coprecipitation. The synthesized HRP&SA/ZIF-8 nanocomposite was then employed as the ideal signal tag for application in the enzyme-linked immunosorbent assay (ELISA) and exhibited excellent sensitivity, selectivity and accuracy in the detection of insecticidal crystalline (Cry) protein Cry1Ab as a transgenic biomarker with a detection limit of 4.8 pg/mL. This proposed method provides a new way for the detection of transgenic biomarkers in food and may inspire further integration of a variety of biomolecules into ZIF-8 for applications ranging from biosensing, biomedicine, and catalysis to energy.

Core-multishell lanthanide-doped nanocomposite by one-pot synthesis for NIR-II emissions-based temperature sensing

The performances of nanothermometers based on visible light are inevitably degraded in biological applications because visible light is greatly weakened after passing through tissues. Herein, in view of the second biological optical transparency window, a type of tailored core-multishell lanthanide-doped nanocomposite was synthesized with facile one-pot coprecipitation method to supplant complex method demanding stepwise thermal decomposition. Proved to have excellent dispersibility, crystallinity, stability and luminous efficiency, the nanocomposite is capable of enhanced NIR-II emissions and a broad temperature detection scope based on three kinds of spectral parameters relevant to its unique core-multishell structure. The maximum absolute and relative sensitivity of luminescence intensity ratios in low temperature range can reach up to 11.3% K−1 and 1.27% K−1, respectively, and a theoretical derivation is provided to address the peculiar V-shaped trend of NIR-II luminescence lifetime. The prepared nanocomposite can serve as a promising candidate for optical thermometer in the fields of cryoablation of diseased tissues and industrial applications in strong magnetic or radiofrequency fields.

Enhanced Bactericidal Action of rGO-ZnO Hybrids Prepared by the One-Pot Co-precipitation Approach.

Metal-based antimicrobials have the potential to profile sustainable solutions to infection care and health. In this study, we report the synthesis of rGO–ZnO hybrid nanostructures by a simple co-precipitation approach with various mass ratios of GO, and their antimicrobial potential was assessed. The structural analysis confirms the presence of a hexagonal wurtzite structure with peak shifting in hybrid nanostructures and increases in crystallite size (11–24 nm). Raman spectra revealed GO doping in the D band (1350 cm–1) and G band (1590 cm–1). Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were performed to investigate the surface morphologies of the synthesized sediments, which showed a change in the morphology of ZnO from non-uniform spherical nanoparticles to a rod-like morphology of the prepared hybrid nanostructures. RAMAN spectra revealed that the retained functional groups on rGO planes were significant in anchoring ZnO to rGO. At lowest and maximum doses of ZnO, substantial bactericidal zones (p < 0.05) for S. aureus (1.55 and 1.95 mm) and E. coli (1.25 and 1.70 mm) were achieved accordingly. Additionally, the inhibition regions were 2.45–3.85 mm and 3.75–6.85 mm for S. aureus whereas (2.05–3.25 mm) and (2.95–3.90 mm) for E. coli at the lowest and maximum concentrations.

Fabrication of ZnO–SnO2 nanocomposite and its photocatalytic activity for enhanced degradation of Biebrich scarlet

The n-n-type ZnO-SnO2 nanocomposite was fabricated using malic acid following a simple one-pot co-precipitation method. The fabricated ZnO-SnO2 nanocomposite was employed as a photocatalyst in the degradation of Biebrich scarlet dye under UV254 light. TEM, SAED, XRD, XPS, EDX, FTIR, and UV spectra have been recorded to characterize the synthesized ZnO-SnO2 nanostructures. TEM studies found that the average particle size was 10-12nm, and the SAED confirmed the polycrystalline nature of the synthesized nanocomposite. It was found that 97% of 10mg/L Biebrich scarlet dye was degraded by 25mg/L of photocatalyst within 40-min irradiation of UV254 light at an optimum pH of 6. Further studies showed that the degradation followed pseudo-first-order kinetics with a rate constant of 5.48 × 10-2min-1. The fabricated ZnO-SnO2 nanocomposite was reusable up to 8 times; hence, it proved to be an efficient catalyst for the photodegradation of Biebrich scarlet dye.

PH-responsive glycine functionalized magnetic iron oxide nanoparticles for SARS-CoV-2 RNA extraction from clinical sample.

The recent outbreak of the novel corona virus disease 2019 (COVID-19) has been made a serious global impact due to its high infectivity and severe symptoms. The Severe Acute Respiratory Syndrome (SARS-CoV-2) RNA extraction is considered as one of the most important steps in COVID-19 detection. Several commercially available kits and techniques are currently being used for specific extraction of SARS-CoV-2 RNA. However, such methods are time consuming and expensive due to the requirement of trained labors, and several chemical reagents. To overcome the mentioned limitations, magnetic RNA adsorption methodology of glycine functionalized iron oxide nanoparticles (GNPs) was established. It showed an efficient potential in SARS-CoV-2 RNA extraction due to pH responsive nature of GNPs. The highly magnetic pH responsive GNPs were synthesized by one-pot co-precipitation method. Random morphology and average 20 nm size of GNPs were denoted by Transmission Electron Microscopy (TEM). X-ray diffractometer (XRD) showed the crystalline magnetite nature. Fourier transform infrared spectroscopy (FT-IR) and UV–visible spectrometry confirmed the presence of glycine on the surface of magnetic nanoparticles. Furthermore, the magnetic nature and thermal properties of GNPs were examined by vibrating sample magnetometer (VSM) and thermo-gravimetric analysis (TGA), respectively. In this study, glycine performed the role of RNA adsorbent. The adsorption of RNA onto the surface of GNPs was achieved in acidic medium (pH 6). In contrary, the elution of RNA from the surface of GNPs was achieved in basic medium (pH 8). The purity of obtained RNA was analyzed by UV–visible spectrometry. Further, the obtained RNA was examined for the presence of SARS-CoV-2 specific Envelope (E), RNA dependent RNA polymerase (RDRP) and Nucleocapsid (N) genes using an RT-PCR analysis. It showed the sudden rise in amount of these genes after 25 cycles of RT-PCR and hence indicated the efficient RNA extraction by GNPs. Agarose gel electrophoresis was used for validation of the quantity and quality of RNA extracted from SARS-CoV-2 patient’s sample. The reusability studies of GNPs were performed by monitoring the repeated use of GNPs for SARS-CoV-2 RNA extraction. This method possesses potential role in the field of disease diagnosis. The extraction results of RNA from SARS-CoV-2 patient’s sample indicated that the GNPs have an outstanding property over the current existing extraction protocols. It leads to the new advancements in extraction and detection of RNA.Graphical Graphical abstract of the pH responsive SARS-CoV-2 RNA extraction by using glycine functionalized magnetic iron oxide nanoparticles (GNPs) which were prepared by modified cost effective one pot chemical synthesis method. Prepared GNPs were characterized by XRD, FT-IR and UV-Visible spectrometry, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Glycine present on the surface of nanoparticles (NPs) played an important role in pH responsive RNA extraction procedure. When nanoparticles added in acidic (pH < 7) medium, glycine gained positive surface charge hence overall surface charge of NPs became positive. Thereby SARS-CoV-2 RNA adsorption/binding occurred on the surface of GNP. Later, the RNA-GNP complex was separated by an external magnet. Separated complex was added in basic (pH > 7) medium to elute RNA from GNP. This phenomenon occurred due to surface negative charge of glycine that caused charge repulsion with RNA. Eluted RNA was examined qualitatively and quantitatively by RT-PCR, nanodrop technique and agarose gel electrophoresis. Results were compared with kit based extracted RNA. Supplementary InformationThe online version contains supplementary material available at 10.1007/s10853-022-07464-6.

Silver nanoparticles anchored magnetic self-assembled carboxymethyl cellulose-ε-polylysine hybrids with synergetic antibacterial activity for wound infection therapy

The severe bacterial infection and chronic wound healing caused by the abuse of antibiotics threaten the public health, which calls the need for the development of novel antibacterial agents and alternative therapeutic strategies. Herein, magnetic carboxymethyl cellulose-ε-polylysine hybrids (FCE) were synthesized via a facile one-pot coprecipitation method and further used as matrix to anchor silver nanoparticles (Ag NPs). The as-resulted Ag/FCE hybrids were employed to inactivate pathogenic bacteria and accelerate bacteria-infected wound healing with the assistance of H2O2. In vitro investigation revealed the combination of hydroxyl radical (·OH) originated from low concentration of H2O2 catalyzed by Ag/FCE and the antimicrobial activity of Ag NPs endowed effective antibacterial performance to the hybrids against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Investigation on antibacterial mechanism indicated antibacterial activity of the synergetic strategy was achieved by destroying bacterial cell integrity, arresting metabolic, producing intracellular ROS, and oxidizing GSH. Additionally, in vivo assay exhibited Ag/FCE possessed satisfactory biocompatibility and effectively accelerated S. aureus-infected wound healing with the presence of low concentration of H2O2. Altogether, the presented results supported the great potential application of the synergistic antibacterial strategy for the therapy of bacterial-infected wound healing.

Angiogenic Hyaluronic Acid Hydrogels with Curcumin-Coated Magnetic Nanoparticles for Tissue Repair.

Angiogenic magnetic hydrogels are attractive for tissue engineering applications because their integrated properties can improve angiogenesis while providing magnetic guidance and stimulation for tissue healing. In this study, we synthesized magnetic nanoparticles (MNPs) with curcumin as an angiogenic agent, referred to as CMNPs, via a one-pot coprecipitation method. We dispersed CMNPs in hyaluronic acid (HyA) to create angiogenic magnetic hydrogels. CMNPs showed a slightly reduced average diameter compared to that of MNPs and a curcumin content of 11.91%. CMNPs exhibited a sustained slow release of curcumin when immersed in a revised simulated body fluid (rSBF). Both CMNPs and MNPs showed a dose-dependent cytocompatibility when cultured with bone marrow-derived mesenchymal stem cells (BMSCs) using the direct exposure culture method in vitro. The average BMSC density increased when the concentrations of CMNPs or MNPs increased from 100 to 500 μg/mL, but the cell density decreased when the nanoparticle concentration reached 1000 μg/mL. CMNPs showed a weaker magnetic response than MNPs both in air and in water immediately after synthesis but retained the magnetism better than MNPs when embedded in the HyA hydrogel because of less oxidation. CMNPs were able to respond to magnetic guidance even when the porcine skin or muscle tissues were placed in between the nanoparticles and external magnet. The magnetic hydrogels of HyA_CMNP and HyA_MNP promoted the adhesion of BMSCs in a direct exposure culture. The HyA_CMNP group also showed the highest secretion of the vascular endothelial growth factor with the release of curcumin in vitro. Overall, our magnetic hydrogels integrated the desirable properties of cytocompatibility and angiogenesis with magnetic guidance, thus proving to be promising for improving tissue regeneration.

Toward efficient dye degradation and the bactericidal behavior of Mo-doped La2O3 nanostructures.

In this study, different concentrations (0, 0.02, 0.04, and 0.06 wt%) of Mo doped onto La2O3 nanostructures were synthesized using a one-pot co-precipitation process. The aim was to study the ability of Mo-doped La2O3 samples to degrade toxic methylene blue dye in different pH media. The bactericidal potential of synthesized samples was also investigated. The structural properties of prepared samples were examined by XRD. The observed XRD spectrum of La2O3 showed a cubic and hexagonal structure, while no change was recorded in Mo-doped La2O3 samples. Doping with Mo improved the crystallinity of the samples. UV-Vis spectrophotometry and density functional theory calculations were used to assess the optical characteristics of Mo–La2O3. The band gap energy was reduced while the absorption spectra showed prominent peaks due to Mo doping. The HR-TEM results revealed the rod-like morphology of La2O3. The rod-like network appeared to become dense upon doping. A significant degradation of MB was confirmed with Mo; furthermore, the bactericidal activities against S. aureus and E. coli were measured as 5.05 mm and 5.45 mm inhibition zones, respectively, after doping with a high concentration (6%) of Mo.

One Pot-Synthesized Ag/Ag-Doped CeO2 Nanocomposite with Rich and Stable 3D Interfaces and Ce3+ for Efficient Carbon Dioxide Electroreduction.

Electrochemical CO2 reduction (ECR) technology is promising to produce value-added chemicals and alleviate the climate deterioration. Interface engineering is demonstrated to improve the ECR performance for metal and oxide composite catalysts. However, the approach to form a substantial interface is still limited. In this work, we report a facile one-pot coprecipitation method to synthetize novel silver and silver-doped ceria (Ag/CeO2) nanocomposites. This catalyst provides a rich 3D interface and high Ce3+ concentration (33.6%), both of which are beneficial for ECR to CO. As a result, Ag/CeO2 exhibits a 99% faradaic efficiency and 10.5 A g-1 mass activity to convert CO2 into CO at an overpotential of 0.83 V. The strong interfacial interaction between Ag and CeO2 may enable the presence of surface Ce3+ and guarantee the improved durability during the electrolysis. We also develop numerical simulation to understand the local pH effect on the ECR performance and propose that the superior ECR performance of Ag/CeO2 is mainly due to the accelerated CO formation rate rather than the suppressed hydrogen evolution reaction.

A pH-responsive cerium-imidazole decorated ZIF-8 to achieve self-healing barrier property for epoxy coating on Al alloy by controlled release

Ce-based imidazole complex (Ce-IM/ZIF-8) nanoparticles (NPs) were fabricated by doping cerium ions (Ce3+ /Ce4+) in zeolite imidazolate framework-8 (ZIF-8) through a one-pot co-precipitation method. The stimuli-responsive release of Ce3+/Ce4+ species from the Ce-IM/ZIF-8 NPs under acidic conditions was confirmed by UV–Vis spectroscopy. Electrochemical impedance spectroscopy and scanning electron microscope were applied to evaluate the corrosion inhibition efficiency of Ce-IM/ZIF-8 NPs on bare aluminum alloy, and it demonstrates that the released Ce3+/Ce4+, Zn2+ ions and imidazole could absorb on the surface of Al alloy by chelating effect, forming a compact corrosion barrier on the Al substrate. Furthermore, the Ce-IM/ZIF-8 NPs were encapsulated into epoxy (EP) resin to obtain a composite coating, and it is found that when the NPs addition amount was 1 wt%, the EP-based composite coating exhibits excellent corrosion barrier and promising self-healing ability, with its impedance at 0.01 Hz maintaining 2.2 × 108 Ω·cm2 even after 6 cycles of aging tests (720 h), which could be ascribed to the synergistic inhibition of released Ce ions and imidazole molecules on Al substrate beneath the defective coating.